I was asked to shoot a large group shot at a conference and supply prints for every attendee by the end of the day. There wasn’t a chance to so a site recci but I was told there was a large open area that would probably be suitable.
A pet hate of mine is seeing large group shots lit by lights (usually soft boxes) either side of the camera so the area is flooded by light. This is a safe option, but not very flattering for the group.
I always look for how can a accomplish a soft light, falling off from one side of the subject to the other with a good balance. On this job, I needed to have 5 speedlights aimed towards the ceiling to the left of camera, 2 speed lights through my interfit softbox, I used the ambient for fill and had a speedlight lighting the ceiling behind the group to add some tone.